Effective nonlinear responses of three-phase magnetoelectric composites

Abstract

A computational method, dubbed simplified unit-cell micromechanics model, is generalized and applied to establish the effective nonlinear responses of three-phase magnetoelectric composites that are composed of two distinct magnetostrictive and piezoelectric phases embedded in elastic polymer matrices. The nature of nonlinear constitutive behavior of each constituent is expected to significantly influence the overall responses of the composites. To obtain the effective nonlinear responses, a mathematical linearization is first introduced to perform the constitutive linearization for the nonlinear materials, and the resulting constitutive equations are then unified and nested into the micromechanics model followed by iterations in order to minimize errors from the linearization process. For the purpose of comparison, we also reformulate the well-established Mori–Tanaka micromechanics model insofar as its mathematical structure is aligned with that of the simplified unit-cell model. Numerical results are first validated against limited experimental measurements available in literature. Parametric studies are then conducted in order to reveal the effect of phase constitutive laws, volume fractions, and geometries on the overall nonlinear responses of there-phase magnetoelectric composites. The contributions of this work complement those of earlier studies that prevalently devoted to two-phase magnetoelectric composites and linear magneto-electro-elastic coupled responses only.

Multiscale simulation and experimental measurements of the elastic response for constructional steel

“…These numerical methods that aimed to efficient achievement of modern compute essentially required finite element discretization of the inhomogeneous region, such as finite element modeling (FEM) 20 , Mechanics of structure genome 21,22 , Fast Fourier transforms 23 and so on. Different from the limited description of physical events of the materials by phenomenological model, the analytical approaches that provide a good reference for revealing the intrinsic properties of materials allow to correlate between the overall behavior of composites and the individual constituents, for instance, elasticity solution [24][25][26][27] , Eshelby theory 28 and energy method 29,30 , which is limited by the complex situation and boundary conditions. Morever, traditional micromechanics is designed to obtain the homogenized characterization at the smallest length scale of the materials 31 , unconsciously ignoring the scale correlation of material deformation mechanism 32,33 .…”

Leveraging the strain transfer at the interface between self-composite CoFe2O4 embedded in pre-sintered Na0.5Bi0.5TiO3 ceramics matrix for the enhancement of magnetoelectric voltage coefficient

“…So far the observed direct ME effect in composites particularly on lead-free (0-3) particulate composites is still very weak leading to the difficulty of using these materials for manufacturing purposes. Hence several groups are working on the ME materials to achieve a high ME coefficient [10][11][12]. Some researchers have reported that the ME coupling coefficient is stronger in the composites depending on the volume fraction of the magnetic phase in the composites [13,14].…”